Short fan sound when I turn on the car ...

[williamsF1]

When I turn on the car after it has been in the garage over night (or perhaps less time) it makes a 1-2 second medium loud fan noise (I think its the fans, maybe exhaust) and then it goes away, it's not as noticable to hear if I drive for a while turn it off and then on again... it's like its like it makes that sound your lips makes if you blow air out with your mouth closed - I never really took notice of this but I would like to hear from you guys if you knew about this. Is it the fans going from zero to high speed or is it something else ?

Does this sound familiar to anyone ? and is this normal ?

[Jeph]

I've heard it before too... rarely in the winter, but more often when it's warmer outside. I don't think it's too uncommon.

[Tool Pants]

Most likely the air pump that comes on for a while when you start a cold engine.